Downward Movement:

Lower your shoulders down in a controlled manner while keeping your lower legs in position.

Inhale while moving down.

Trainer Tip:

As a beginner, it is important to perform a posterior pelvic tilt prior to performing the crunch. To do this, press your lower back into the floor while curling your pelvis slightly upward. This will help you engage the right muscles.

Stop when you feel tired. Build your resistance slowly.

Modifications:

There are a few modifications that can make the exercise more challenging:

Bring your feet off the floor. Make a right angle at your hip and bend your knees so your lower legs are parallel to the floor.

Do the exercise while balancing on a stability ball.

Warnings:

Avoid pulling up or jerking on your head with your hands. This could cause injury to the neck. Keep your hands light on your head and concentrate on using your abdominal muscles to do the crunch. Make sure to maintain correct technique even as you fatigue.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Bent-knee sit-up/crunches. American Council on Exercise website. Available at: http://www.acefitness.org/acefit/fitness%5Fprograms%5Fexercise%5Flibrary%5Fdetails.aspx?exerciseid=52. Accessed November 14, 2014.

When pigs crunch: A commonsense approach to abdominal training. American Council on Exercise website. Available at: http://www.acefitness.org/certifiednewsarticle/1884/when-pigs-crunch-a-commonsense-approach-to. Accessed November 14, 2014.